Ice saw



May 5, 1925. v 1,536,783

` s. T. FREAs ET AL ICE SAW Filed March 25, 1922 2 sheets-sheet e T0 all who/m, t may conce/mw,

Patented May 5, 1925. l

UNITED srArr PATENT SAMUEL T. ranas; or 'rann'iioia NEW Jansma?, anni WILLIAM n. mannen, er. intrin- DELPHIA, PENNSYLVANIA, Assreiveast rro: HENRY nissaoim a sons, incomo- RATED, OFPHILADELPHIA, riimsirnvema, A conrenarioit onriiiiitsxgtvanm.

- 1er. SAW.

Be it known that we, SAMUEL Fincas `and VVILLIAiir E., Temen, citizens ofr` the United States, residing, respectively, in Trenton- Mercer County, New Jersey, and Philade phia, Pennsylvania, have invented certain Improvements' in Ice Saws, of which the following is a specification.

One object of our invention is to design an improved ice; cutting saw of the type in.

which the feed can be controlled by the saw and the mechanism by which the saw is driven can be propelled overthe ice at a predetermined speed.

A further object of the invention is to construct the saw so as to limit the feed per revolution and also to prevent the saw.

hammering in the kerf. Y

These 'objects we attainrin the following manner, Vrefe-rence being had to the accompanying drawings, in which. n

Fig; 1 is aV view of'suiticient ofa sawto illustrate our invention and showing the cuts of several teeth in the ice;

Fig. 2 is an enlarged Iview showing more clearly the action of two of the teeth and the design of theportion of the blade back of each tooth; and

Fig. 3 is a view of a` modified forni of saw having integral teeth. i

1 is the blade of a circular saw having a series of recesses 2 at tlieperiphery for the receptionV of the teeth 8 and the segmental locking plates 4. In the present instance,

each locking plate and tooth is grooved at the back to receive the V-'shaped edge 5 of the wall of the recess. Each tooth has a shoulder 6 at the back ofthe point, abutting against the portion 7 back of the tooth. The point 8 of the tooth is shaped viii the manner shown in Fig. l to provide the correct bite to cut the ice.

The top of each tooth is given suoli a rake that it conforms with the edge of the portion 7 of the blade, generating a curve, which is the korf cut in the ice by a single tooth when the saw is cutting the ice and propelling the machine on which it is mounted.

The curve of the tooth 3 is shown by the line w. The curve of the tooth 3" is shown.

hindrance.

Application tiled March 25, 1922. Serial No. 546,?26.

f of eacl'i'tooth graduallyk falls awayifroin. the

curve of' the tooth. after it enters the ice,

consequently, vthere vis no. hammering of the saw in the lerf and there is sniicient clearance to allow each tooth to The method'y of determining the curve is as follows: For machines of Vdiiferent horsey power, the feed must becontrolled, first, to prevent stalling, or overload, and, second,

to snit the operator so thathe can .walk atk 'such a speed as is convenient for khim to have control of the machine. Obtaining the j required feed, and noting the circumference of the saw, the curve, which is a reproduction of the lrerf cut in the ice by the saw, can be readily plotted. From this curve, the back of the projection of the saw is designed. The portions 7 serve ask checks and control the feed perrevolution, making each tooth n take a proportional part in cutting.

By so designing the bladek back of the tooth, hammering vis eliminated and by having each portion 7 of the saw conform with the kerfwhe-n it starts to cnt, it remains in cont-act with it until it has cnt the length of the portion conforming,A to the predeteri mined curve.

`Each tooth travels in a given path, one ltooth cutting in advance ofthe other and the curve of the cut of four teeth is as shown in Fig. 1. As each tooth makes its eut, the

machine is moving forward a .given dis-` tance, dependent upon the shape of the portioirof the blade back of each tooth.

Fig. 2 of the drawings shows the teeth adcut without o-FFifoE.. n

vanced a -part ofa revolution, the tooth 30 i having cut a kerf farther into the ice, the tooth 3d having entered they ice. The top of said tooth 3d and the outer edge of the portion 7 back of the tooth have an extended bearing against the ice in the` kerf, as at y, from the point Sk of the tooth to a line a. From the line L the portion 7 has an abrupt curve` away from the kerf.

The bearing of the tooth as it advaneespinV the ice gradually decreases, the line of contact heilig comparatively short, as at g/,f

Fig. 2, and, when the tooth is at the full depth of the kerf, as at y2, Fig. 1,`then only the point of the r tooth is incontactpwith the ice.

By thisarrangeinent,-the feed of the saw i is controlled by the teeth as they enter the ice, and, consequently, the other teeth in the kerf cannot cnt into the ice more than the predetermined depth.

lVhile in Figs. l and 2 a Saw having in- 5 'Sertable teeth is shown, the saw may be made,

as in Fig. 3, with teeth 3e integral with the blade la.

YVe claim:

1. A Circular ice cutting saw of the selffeeding typo having a series of teeth at its periphery,the edge oi the saw back of the point of each tooth being convexly curved and conforming approximately to the cnrvature of the initial part of the kerf cnt by the said tooth when the saw is fed at a predetermined rate.

2. A circular ice cutting,- saw of the SeliL feeding type having a. series of teeth at its periphery, the edge oi the saw back oi the point of each tooth diverging inward from a concentric circle extending through the said point and also being eonvexly curved in approximate conformity with the curvature of the initial part of the kerf ont by the sa id tooth when the said Saw is fed at a predetermined rate, the said edge of the Saw back of each tooth being thus adapted to smoothly engage the kerl and to have an extended but gradually decreasing Contact therewith whereby it serves to control the depth of ont of other teeth.

SAMUEL T. FREAS. WILLIAM E. TRETCH. 

